Lens-marking machine



condition.

' preferred Patented Dec. 12,- 1922.

n Ira r LENS-MARKING MACHINE.

Application filed. February 7,1922. i serial No. 534,819.

To all whom it may concern:

Be it known that I, ALBERT E. CovnLLn, a citizen of the United States, residing at West Medford, in the county of Middlesex and State of Massachusetts, have invented certain new and useful Improvements in Lens-Marking Machines, of which the following is a specification.

The invention relates to machines for use in marking lenses preparatoryto trimming them, grinding their edges, and mounting them in a frame or nose piece.

After the faces. of the, lens have been ground, the opticalcenter isnext found and marked, this operation being performed with apparatus now commonly used by Opticians. At this time, also, the axis of the lens, if it has a cylindrical grinding, is determined and marked. If the lens is to be de-centered it is placed on a lens marking chart having a multiplicity of lines designed to assist the Optician in. determining the degreeof de centration and marking the geometrical center of the lens. These lines also assist the optician in marking the horizontal axis, and if desired, also. the vertical axis of the lens, so as to assist him in placing the lens properlyin the edge grinding machine. and in locating the lens accurately in the frame or nose piece.

The lensmarking charts above, referred to containsuch a multitude of lines, in order toadapt them for use under a great variety of conditions, that they are very confusing and great care is required on the part ofthe optician to avoid making errors in performing the marking operation, particularly if the lens has a complicated grinding. It is the chief object of the present invention, therefore, to devise a machine orapparatus in which'this marking operation. can be performed with greater accuracy and facility, in which the liability of making errors will be substantially eliminatech and which can be adjusted quickly to practically any, set of Thcnature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in theappended claims. Referring now to the drawings, Figure 1 is a plan view of a machine embodying the invention in the'form at'present Fig. 2 is a plan View of the gearing used in the machine; a

Fig. 3 is a central cross sectional. view of the machine shown in Fig. 1; Fig. 4 is a plan view-of alens ready to be marked in this machine; and y I f Fig. 5 is a plan view showing certain steps of the marking operation.

The machine shown comprises a central disk 2 of circular outline having two geometrical axes thereonat right angles to each other, as indicated at 3 and 4. 'At one side of theaXis 4 is a series of lines 5, preferably spaced apart by intervals of one mm.,'and

forming a scale to assist the workman in determining the proper degree of decentration. Consequently, th1s scale, may be referred to as a decentering scale. The disk 2 is secured to the upperface of a part 6 which rotates on a pin or stub shaft 7 se:

cured fast in a base plate 8. This member 6 forms, in effect, a'hubfor a is secured to said member.

lilncircling the disk 2 is an annular disk 10 having a line liZ eXtending diametrically thereacross and designed to designate the location of the axis of the cylindrical grinding' of the" lens. This disk preferably is mounted in the same'plane With thedisk 2,

pinion 9' which and it issecnred fast to the upper surface of an annular plate 14 which is mounted on a reduced part of the hub 6 and is guided thereon, as clearly shown in 3. An

annular gear 15 is secured to the lower face of the plate 14 in any convenient manner. The annular plate 14' fits snugly within an other annular member 16 which is secured to the base plate 8 by spacing studsor rivets. Mounted on certain of these studs are gears 17] and 18, respectively, which mesh with the respective gears?) and 15,the margins of the gears 17and18 projecting beyond the base 8 so that they may be conveniently Inanip'ulated by the workman. A spring plate l9bears against the face of the gear 17 and serves. to exert a frictional drag on it and thus tends to maintain it, and the central disk, in their adjusted positions.

There is sufficient friction on the annular plate 14: to keep the disk 10 from turning accidentally. r

A. circular scaleQO, graduated in degrees, encircles the annular disk 10 and serves'to indicate the angular position of the line 12. This scale issupported on the upper surface of the part 16. The disks 2 andlO and the scale 20 are all covered and protected by a transparent faceplate 21, preferably made of glass or celluloid, and having vertical and horizontal axes 22 and 23 marked thereon. This face plate; is held in place by a marginal ring 2 1 and screws 25 which extend through the ring and are threaded into the plate 16. The edges of the ring 24, base plate 8, and the intermediate stationary parts are substantially flush. with each other, with the gears 17 and 18 projecting beyond the marginal edges of these parts so that they may be conveniently manipulated by the workmans fingers.

For the purpose of explaining the use of the machine let it be assumed that a lens L, Fig. 4, has both spherical and cylindrical grindings and that it is to be set in a frame decentered to the right four mm., and with the axis at 45, The optical center C,-Fig. 4:, is first found and inarkedby anink dot; and at this time, also, the axis of the cylindrical grinding is determined and designated by dotsA and Thework'man next sets the central disk 2 with the dec'entering scale 5 at the right, as shown in Fig. 5, (since the lens is to be dec'e'ntered to the right) and he adjusts the annular disk 10 to bring the line 12 into the 45 position, as shown in Figs. 1 and 5. He then places the lens L on the machine with theoptical center C superposed on the center of the central disk 2, and the axis or line A--B superposed on the line 12. NVith thepartsfin this position he makes dots or marks D and E on the lens at points superposed'on th horizontal axis 23 to designate the horizontal geometrical axis of the lens. lVhile-heholds these marks D and E'ontheaxis 23 heinoves thelens L to the right'four mm, thus mov- 1n comblnatlon, a central dlsk having a deing the optical center 0 to the position shown in Fig. 5. Theaxis Al -B is nowoftset with reference to the line 12 but is parallel thereto. The workman now makes a mark or dot-at F, Fig. 5, immediately o 'er the center of-the central disk 2, and this dot F will be used as the geometrical center of the lens intrimming it and grinding its edge to the desired outline, If desired, marks may also be made at this time atG and H at points above the line 22 to indicate the vertical geometrical axis of the lens. The markings of these geometrical axes and of the geometricalcenterF not only are use fill in guiding the workman in cutting the lens to the required shape grinding its edge, but they are-equallyvaluabl'e as guides in properly locating the lens in the frame or nose piece.

If the lens were to be decentered downwardly the scale 5 would be located below the axis 4:, asshown in Fig, 1, and instead of guiding the lens on the horizontalaxis 23 in moving it to its decentered position,

it would beignidedon the vertical *axis .22.

cal axes on the lens.

combination, a central disk having a d In other words, the central disk 2 is adjusted with the scale in the direction-in which the lens is to be decentered and the axes 22 and 23 are subsequently used, both to guide the operator in moving the lens to its decentered position, and also in marking the geometri- The line 12 on the annular disk is always adjusted to the angular position of the axis prescribed for the cylindrical grinding of the lens. I j

It will now be appreciated that the machine can be set very quickly to agree both with the direction of decentration and also the position of the axis of the cylinder. The workman can tell at a glance whether the machine is set to agree with the prescription, and he can then mark his lens without being confused by lines additional to those that he needs in performing the marking operation. The marking operation, therefore, is facilitated and the liability of making errors is substantially eliminated.

While I have herein shown and described the best embodiment of the invention of center of said central disk and having means 7 thereon to designate an axis, a transparent plate covering said disks and having two geometrical axes thereon at right angles to each other, and a scale cooperating with said second disk.

2. A lens marking machine comprising,

centering scale thereon, a second diskad v justalole about the center of said central disk and having means thereon to designate an axls, said disks being relatively adjustable about the centerof the central disk, atransparent plate covering said disks and having 3. A lens marking machine comprising-in centering scale thereon, a second disk adjustable about the center of said central disk and having means thereon to designate an axis, said disks being relatively' adjustable about the center of the central disk, a transparent plate covering said disks and having two geometrical axes thereon atright angles to each other, a scale cooperating with, said second disk to indicate its angular: position, and means for adjusting said disksabout said center independently of each other.

4:. A lens marking machine comprising,

in combination, a central disk having a decentering scale thereon and also having thereon two geometrical axes at right angles to each other, a second disk of substantially greater diameter than the first disk and having a line located diametrically thereon to designate an axis, said disks being relatively adjustable about the center of the central disk and being in substantially the same plane, a transparent plate covering said disks and having two geometrical axes thereon at right angles to each other, and

a scale cooperating with saic second disk to indicate the angular position of said line.

5. A lens marking machine comprising, in combination, a central disk having two geometrical axes thereon at right angles to each other and also having thereon a decentering scale at one side of one of said axes, a second disk of substantially greater diameter than the first disk and having a line located diametrically thereon to desig nate an axis, said disks being relatively adjustable about the center of the central disk and being in substantially the same plane, a transparent plate covering said disks and having two geometrical axes thereon at right angles to each other, and a scale cooperating with said second disk to indicate the angular position of said line.

6. A lens marking machine comprising, in

combination, a central disk having a scale thereon, a second disk adjustable about the center of said central disk and having means geometrical axes thereon at right angles to each other, means for adjusting said disks about a common axis, means supporting said plate substantially in contact with said disks, and a scale cooperating with said second disk to indicate its angular position.

7. A lens marking machine comprising, in combination, a central disk having a decentering scale thereon, an annularv diskencircling said central disk and having a line extending diametrically thereacross, both oi said disks being adjustable about the center of the central disk, a transparent plate covering said disks and having two geometrical axes thereon at rightangles to each other, and a scale cooperatlng with'saidannular disk to indicate the angular position of said line. i

8. A lens marking machine comprising, in

combination, a central disk having a decentering scale thereon, an annular disk encircling said central disk and having a line extending diametrically thereacross, a pinion fast with said central disk, an annular gear fast with said annular disk, gears meshing, respectively, with said pinion and annular gear for adjusting said dis rs, a transparent plate covering said disks and having two geometrical axes thereon at right angles to each other, and a stationary scale encircling said annular disk and graduated in degrees.

ALBERT E. COVELLE. 

